Jug Brook

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Jug Brook
Basin:	St. Lawrence
State or Province:	Vermont
Country:	USA
Latitude:	44.899711
Longitude:	-72.058878
School:	North Country

The following are the most common invertebrates collected from this stream site. This site needs additional work. If there are interested individuals sampling this stream please contact Declan (dmccabe@smcvt.edu) to improve this site.

Chironomidae

Order

Diptera

Family

Chironomidae

Common name

Nonbiting midge

Tied fly

Griffith's Gnat

Midge larvae tend to be the most common macroinvertebrate at our sites. As with other Diptera, there are no true jointed legs. Chironomidae do have a pair of prolegs at each end and preserved individuals tend to curl into a 'C'. Identification past family requires slide-mounted heads. We have seen philopotamid caddisflies misidentified with the chironomids and we suspect that that happens when samples are being sorted from trays. Under a microscope, six prominent legs can be seen on members of the caddisfly family Philopotamidae.

More information on Philopotamidae.

Perlidae

Order

Plecoptera

Family

Perlidae

Common name

The Golden Stonefly Creeper

Tied fly

Connecticut Curler

This stonefly is characterized by the three pairs of filamentous gills located on the sides of all three thoracic segments. It is distinguished from the family Pteronarcyidae by the absence of gills on the abdominal segments. Often, the thoracic terga are brightly patterned as pictured, though this is not always the case. Another important feature is that the paraglossae and glossae extend different lengths.

Images of filamentous gills and the family Pteronarcyidae.

Genera commonly encountered in this family include Acroneuria, Agnetina, and Paragnetina. Less commonly, we have found Perlesta.

Very rarely encountered genera include Neoperla and Hansonoperla. If you believe you have found either of these, please send a specimen our way!

Hydropsychidae

Order

Trichoptera (caddisfly)

Family

Hydropsychidae

Common name

net spinning caddisfly

Tied fly

Emergent Sparkle Pupa, Vermont Hare's Ear

This family of net-spinning caddisflies is very abundant at several sites. They are important filtering collectors and are quite common at urban and agricultural sites where particles of organic material can be important food resources. Genus-level identification is possible for mature specimens and we will include the genera we found at your site if possible.

When using the key, some features that are challenging to see are the forked trochantin and the paired sclerites in the folds between segments. Other, more easily seen key features include filamentous gills on the abdominal segments and the sclerotization of the dorsal surfaces of all three thoracic segments. Keep in mind that with smaller or more immature specimens, genus-level ID may not be possible.

Commonly found genera include Cheumatopsyche, Ceratopsyche, and Hydropsyche. Less commonly, we have found Arctopsyche and Potamyia.

Images of the forked trochantin and the paired sclerites.

Elmidae

Order

Coleoptera

Family

Elmidae

Common name

riffle beetle

We very commonly find adult and larval riffle beetles. The adults are clearly beetles, but the larvae can be confused with other orders. The forward pointing tooth on the front end of the larvae as described in the key can be a challenge to see, particularly in small individuals. Larvae are characterized by having a single tarsal claw at the end of their legs, which have 4 segments. Adults, on the other hand, have two tarsal claws at the end of each leg. Commonly encountered genera include Dubiraphia, Macroychu, Optioservus, Phanocerus, Promoresia, and Stenelmis.

Images of the adult and larval riffle beetles.

More information on Dubiraphia, Macronychus, Optioservus, Phanocerus, Promoresia, and Stenelmis.

Psephenus

Order

Coleoptera

Family

Psephenidae

Genus

Psephenus

The true "water penny" is commonly found in the waters sampled. Psephenus has a rounded shape with relatively smooth edge. The false water penny, whose edges are serrated, has a more oval appearance. The gills on the ventral surface are found only in the true water pennies.

Another genus encountered in this family is Ectopria.

Gomphidae

Order

Odonata

Family

Gomphidae

Common name

clubtail dragonflies

Like other Odonata, members of this family have four wingpads. Like members of the sub-order Anisoptera, the abdomen terminates in five points. What distinguishes Gomphidae from Aeshnidae is the fact that Gomphidae has clubbed antennae.

Image of the four wingpads and the abdomen.

More information on Aeshnidae.